World-wide environmental concerns have generated a broad range of new national and international waste regulations. In particular, the Marine Plastic Pollution Research and Control Act of 1987 (United States Public Law 100-220) and Annex V of the International Convention for the Prevention of Pollution from Ships (MARPOL) limit the overboard discharge of unpulped trash from ships. U.S. Navy regulations and policy (OPNAVINST 5090.1A) prohibit the discharge of (floating) solid waste within certain areas. Accordingly, shipboard trash compactors need to generate high-density trash slugs that are negatively buoyant.
Research has shown that negatively buoyant trash slugs can be formed in compactors having an extremely high compacting ram face pressure (e.g. 440 pounds per square inch). Commercially available, high-pressure trash compactors use a compacting ram to: 1) compact the trash into a trash slug within a stationary compaction chamber, and 2) eject the compacted trash slug from the stationary compaction chamber. However, ejection of the trash slug in this manner results in a certain amount of trash delamination as the trash slug exits the compaction chamber. Shear forces act on the sides of the trash slug as the slug is pushed from the compaction chamber causing trash slug delamination. Unfortunately, delamination frequently prevents the trash slug from achieving negative buoyancy even if the compacting ram is capable of generating the necessary compaction forces within the compaction chamber.